1. Field of the Invention
This invention relates to a tape recorder or more in particular to an operating mechanism of the tape recorder.
2. Description of the Prior Art
Generally, the tape recorder is so operated that upon switching from a stop state to a playback or recording state, four internal motions occur. They include, firstly, movement of the magnetic head and like to a playback position and engagement thereof in that position; secondly, the pinch roller coming into contact with the capstan; thirdly, the take-up roller, which derives its power from a motor, coming into contact with the take-up reel mount; and fourthly, the releasing of the brake plate which, in contact with the take-up reel mount and the supply reel mount, has thus far applied braking force to the pair of reel mounts.
These four operations are generally derived from the movement of the playback operating member from the stop position to the playback position. In the conventional tape recorders, each of the four operations is performed through individual parts controlled by the movement of the playback operating member, with the result that various inconveniences are caused by the difference in timing of completion of the four operations.
As an example, the fault due to the difference in timing between the second and third motions mentioned above will be described. Generally, the second operation is one in which the tape is fed at fixed speed by being held between the capstan rotated at fixed speed and the pinch roller in free rotation. The third operation, on the other hand, is for taking up on the take-up reel mount the tape supplied through the capstan and the pinch roller. Since the rotational speed of the take-up reel changes with the thickness of the convolutions of the tape taken up thereon, the tape take-up speed of the take-up reel mount is generally set at a level higher than the tape supply speed of the capstan and pinch roller, so that the difference in speed therebetween is absorbed into a slip mechanism provided on the take-up reel mount. If the second operation is completed earlier than the third operation, the tape is supplied from the capstan while the rotation of the take-up reel mount is delayed, thus forcing out the tape. In the event that the completion of the third operation is earlier than that of the second operation, by contrast, the tape is taken up at undesirably higher speed.
If the difference in timing between the first and fourth operations occurs in addition to the above-mentioned fault, a more complicated inconvenience results. These faults present themselves more conspicuously when the playback operating member is operated slowly.
Prevention of these faults requires proper timing of the four operations. For this purpose, the parts participating in the four operations are required to be produced in high precision, and also the adjustment of timing is necessary in assembling such parts, resulting in a high production cost.
Although the foregoing description is primarily concerned with the playback operation, the same principle applies also to the timing of switching from playback to pause mode or suspension of operation. In this case, the operations reverse to the second, third and fourth operations mentioned above are in principle required. In the conventional tape recorders having the pause mechanism, however, the pinch roller is moved away from the capstan and the take-up roller away from the take-up reel mount, but the brake plate is not brought into contact with the pair of reel mounts. The resulting disadvantage is that the reel mounts fail to stop accurately, thereby continuing to feed the tape by inertia.